Electric switch

ABSTRACT

An electric switch includes a single insulator supporting infeed and outfeed terminals at its opposite ends, and a switch arm is pivoted to the outfeed terminal for releasable connection to the infeed terminal. The infeed terminal is arranged for connection to, and support of the switch by, a main infeed bus, with the switch arm movable in a plane parallel to the longitudinal axis of the bus, and the outfeed terminal is arranged for connection of one or more outfeed conductors.

7 United States Patent [1 1 Kerr [11] 3,872,267 1451 Mar. 18, 1975 1 ELECTRIC SWITCH [76] Inventor: James A. Kerr, Rt. 4, Box 319C,

l-lillsboro, Oreg. 97123 [22] Filed: Oct. 9, 1973 211 Appl. No.: 404,423

[52] US. Cl 200/48 R, 337/193, 174/169 [51] Int. Cl. H0lh 31/00 [58] Field of Search 174/169; 200/48 R, 49; 337/187,191, 193

[56] References Cited UNITED STATES PATENTS 2,025,321 12/1935 Walsh 337/193 2,103,056 12/1937 Birkenmaier 337/193 X 2,301,551 11/1942 Kyle 174/169 2,700,712 l/1955 Stinson 337/193 2,779,815 l/1957 Sokol 174/169 Primary E.\'aminerHerman Hohauser Attorney, Agent, or Firm-Oliver D. Olson [57 ABSTRACT An electric switch includes a single insulator supporting infeed and outfeed terminals at its opposite ends, and a switch arm is pivoted to the outfeed terminal for releasable connection to the infeed terminal. The infeed terminal is arranged for connection to, and support of the switch by, a main infeed bus, with the switch arm movable in a plane parallel to the longitudinal axis of the bus, and the outfeed terminal is arranged for connection of one or more outfeed conductors.

6 Claims, 4 Drawing Figures ELECTRIC SWITCH BACKGROUND OF THE INVENTION This invention relates to electrical switches, and more particularly to a novel electric switch construction for releasably connecting one or more outfeed conductors to a main infeed bus.

Electric switches of the general class described above have been provided heretofore. Most of them utilize a pair of insulators, one supporting an infeed terminal and the other an outfeed terminal, with a switch arm releasably interconnecting the terminals. In another form of switch provided heretofore, a single insulator mounts the infeed and outfeed terminals at its opposite ends, with a switch arm releasably interconnecting the terminals. In both of these forms the insulators are mounted on a base supported independently of the main infeed bus. This arrangement requires that a structural support for the base be provided and located adjacent the main infeed bus in the area ofdesired connection. This involves excessive costs of components, assembly and installation, and requires excessive room in the area of desired installation to allow an operator the necessary freedom of safe movement in front of the switch. Moreover, the infeed terminals of these switches generally are limited in utility to connection to a specific size and shape of bus, thereby requiring an inventory of a wide range of sizes and shapes of infeed terminals to accommodate connection to a correspondingly wide range of sizes and shapes of infeed buses.

SUMMARY OF THE INVENTION In its basic concept, the electric switch of this invention utilizes a single insulator to support at its opposite ends infeed and outfeed terminals adapted for connection to diverse types and shapes of electrical infeed buses and outfeed conductors, the infeed terminal also serving to support the switch by the infeed bus to which it is connected.

It is by virtue of the foregoing basic concept that the principal objective of this invention is achieved; namely, to overcome the aforementioned disadvantages of electric switches of the prior art.

Another important object of this invention is the provision of an electric switch of the class described which is capable of connection to infeed buses of diverse shapes and sizes. with speed and facility.

A further important object of this invention is the provision of an electric switch of the class described which utilizes the infeed bus as its sole means of support, whereby to accommodate installation of the switch for maximum versatility of use and for operation in a minimum of space.

The foregoing and other objects and advantages of this invention will appear from the following detailed description, taken in connection with the accompanying drawing of preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a view in front elevation of an electric switch embodying the features of this invention.

FIG. 2 is a view in side elevation as viewed from the right in FIG. I.

FIG. 3 is a fragmentary view in front elevation of the outfeed terminal component of the switch shown in FIG. 1, illustrating the manner of attachment of an additional outfeed conductor. a

FIG. 4 is a fragmentary view in front elevation, similar to FIG. 1, showing a modified form of infeed terminal component of the electric switch.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring primarily to FIGS. 1 and 2 of the drawing. the electric switch of this invention includes a single, elongated electrical insulator 10. It is constructed of any of the well known types of electrical insulation material, such as ceramic, and preferably is hollow through its length to minimize its weight.

The opposite end portions of the insulator serve to mount electrical terminals. Thus, the outfeed terminal 12 includes a mounting section in the form of a hollow socket 14 which receives one terminal end portion of the insulator for positive attachment thereto, as by means of a suitable cement or other bonding agent. The outfeed terminal also includes an integral connector section. In the embodiment illustrated, the connector section is provided as a standard four-hole NEMA pad 16 for association with a standard cap 18 and clamp bolts 20. As is well known, this type of terminal accommodates the connection of one or a plurality of outfeed conductors 22, as illustrated in FIG. 2. Further, the connector also accommodates the attachment of a conventional type terminal adapter 24 for outfeed conductors 26 of the tube type (FIG. 3).

The outfeed terminal also includes an integral mounting bracket 28 for a switch arm 30. In the preferred embodiment illustrated, the outer end of the bracket is provided with an opening for the reception of a pivot bolt 32. The bolt extends through one end of the switch arm and through said opening and is provided with a clamp nut 34. A spring washer 36 between the bolt and switch arm maintains the latter in resilient frictional engagement with a smooth finished contact surface 38 on the bracket. A projecting pin 40 on the bracket is arranged to engage a surface 42 on the switch arm to limit the degree of opening of the latter.

The opposite end of the insulator 10 mounts an infeed terminal 44. This terminal also includes a mounting section in the form of a hollow socket 46 arranged to receive the end portion of the insulator and to be secured thereto, as previously explained. The infeed terminal also includes an integral bracket 48 which supports contact and latching mechanism for association with corresponding contact surfaces and latches mechanism on the switch arm 30, all of which is of conventional construction.

The infeed terminal also includes an integral connector section for attachment to a main infeed bus 50. In accordance with this invention, the connector section of the infeed terminal is constructed and arranged to accommodate attachment to infeed buses of various sizes and shapes, to support the entire switch assembly the the infeed bus, and to dispose the switch arm for movement in a plane substantially parallel to the longitudinal axis of the infeed bus.

In the embodiment illustrated in FIGS. 1 and 2, the connector section includes a saddle-shaped socket member 52 proportioned and arranged to engage a portion of an infeed bus 50. Associated with the socket member is a clamp member 54 of reverse saddle shape arranged to engage a portion of the bus opposite the socket member. Spaced bolts 56 interconnect the socket and clamp members for moving the clamp member adjustably toward and away from the socket member, whereby to releasably secure the bus therebetween.

The opposing saddle-shaped members 52 and 54 accommodate attachment of the switch to infeed buses 50 of various sizes and shapes. Thus, the infeed bus may be of circular cross section, as illustrated, of varying diameters, or it may be of rectangular or of other non-circular cross section of diverse dimensions.

In the embodiment illustrated in FIG. 4, the connector section of the infeed terminal includes a socket member in the form of an open hook 60 arranged to engage a portion of an infeed bus 50, and the clamp member is in the form of an elongated threaded screw 62 arranged to engage a portion of the infeed bus opposite the hook. For this purpose the connector section includes a projecting boss 64 having a threaded opening mounting the screw for adjustment of the inner end thereof toward and away from the hook. Although this form of connector section is limited primarily to use with infeed buses of circular cross section, it affords attachment and detachment relative thereto with greater speed and facility than does the form illustrated in FIGS. 1 and 2.

It is to be noted that the connector sections of both of the embodiments of FIGS. 1 and 4 function to support the entire switch assembly by the main infeed bus 50. Typically, the switch is mounted on the busin a downwardly suspending condition, as illustrated best in FIG. 2. In any event, the support of the switch directly by the main bus, as distinguished from the prior requirement of a separate support for the switch, allows the switch to be positioned at any desired location along the length of the bus. Moreover, when mounted in the suspended condition illustrated in FIG. 2, the operator may operate the switch from underneath, thereby minimizing the area required for safe operation of the switch.

It is to be noted further that the connector section of the infeed terminal is so arranged that the switch arm 30 is movable pivotally about the axis of the pivot bolt 32 in a plane which extends substantially parallel to the longitudinal axis of the bus. This arrangement minimizes stresses and strains on the bus incident to the opening and closing of the switch arm.

In the preferred embodiment illustrated, the switch arm 30 extends substantially parallel to the longitudinal axis of the insulator when the switch arm is in the switch-closing position illustrated in FIG. 2. Further, the infeed terminal connector section 52, 54 is disposed with its longitudinal, bus-clamping axis forming with the closed switch arm an included obtuse angle which faces away from the insulator. The opening of the switch arm thus is in a downward direction away from the main bus, thereby providing a fail-safe condition in the event of inadvertent opening of the switch arm.

From the foregoing it will be appreciated that the present invention provides an electric switch of simplifled and therefore economical construction, which is of minimum weight and bulk for convenient transport and practicable support by an infeed bus at any desired location, for fail-safe operation with minimum stress on the bus.

It will be apparent to those skilled in the art that various changes may be made in the size, shape, type, number and arrangement of parts described hereinbefore, without departing from the spirit of this invention.

Having now described my invention and the manner in which it may be used, l-claim:

I. An electric switch, comprising:

a. an elongated electric insulator,

b. an electrically conductive infeed terminal on one end of the insulator,

c. an electrically conductive outfeed terminal on the opposite end of the insulator,

d. an elongated, electrically conductive switch arm connected pivotally to the outfeed terminal for movement between a switch-closing position engaging the infeed terminal and a switch-opening position disengaged from the infeed terminal,

e. the infeed terminal having a connector section arranged for releasable attachment to an infeed bus for supporting the switch by the bus with the switch arm movable in a plane disposed substantially parallel to the infeed bus, and

the outfeed terminal having a connector section arranged for releasable attachment of an outfeed conductor.

2. The electric switch of claim I wherein the connector section of the infeed terminal is arranged to dispose the longitudinal axis of the switch arm, when the latter is in said switch-closing position, to form with the longitudinal bus-clamping axis of said connector section an included obtuse angle facing away from the insulator.

3. The electric switch of claim 2 wherein the switch arm extends substantially parallel to the insulator when in said switch-closing position, and the connector section of the infeed terminal is disposed at an angle to the longitudinal axis of the insulator.

4. The electric switch ofclaim 1 wherein the connector section of the infeed terminal comprises a socket member arranged to engage a portion of an infeed bus, and a clamp member adjustable toward and away from the socket member for engaging a portion of the bus opposite the socket member.

5. The electric switch of claim 4 wherein the socket member comprises a hook, and the clamp member comprises a threaded screw.

6. The electric switch of claim 4 wherein the socket member comprises a saddle-shaped member, and the clamp member comprises a second saddle-shaped member and adjustable securing means interconnecting said saddle-shaped members. 

1. An electric switch, comprising: a. an elongated electric insulator, b. an electrically conductive infeed terminal on one end of the insulator, c. an electrically conductive outfeed terminal on the opposite end of the insulator, d. an elongated, electrically conductive switch arm connected pivotally to the outfeed terminal for movement between a switch-closing position engaging the infeed terminal and a switch-opening position disengaged from the infeed terminal, e. the infeed terminal having a connector section arranged for releasable attachment to an infeed bus for supporting the switch by the bus with the switch arm movable in a plane disposed substantially parallel to the infeed bus, and f. the outfeed terminal having a connector section arranged for releasable attachment of an outfeed conductor.
 2. The electric switch of claim 1 wherein the connector section of the infeed terminal is arranged to dispose the longitudinal axis of thE switch arm, when the latter is in said switch-closing position, to form with the longitudinal bus-clamping axis of said connector section an included obtuse angle facing away from the insulator.
 3. The electric switch of claim 2 wherein the switch arm extends substantially parallel to the insulator when in said switch-closing position, and the connector section of the infeed terminal is disposed at an angle to the longitudinal axis of the insulator.
 4. The electric switch of claim 1 wherein the connector section of the infeed terminal comprises a socket member arranged to engage a portion of an infeed bus, and a clamp member adjustable toward and away from the socket member for engaging a portion of the bus opposite the socket member.
 5. The electric switch of claim 4 wherein the socket member comprises a hook, and the clamp member comprises a threaded screw.
 6. The electric switch of claim 4 wherein the socket member comprises a saddle-shaped member, and the clamp member comprises a second saddle-shaped member and adjustable securing means interconnecting said saddle-shaped members. 